Maxwell’s demon is usually interpreted to imply some kind of sorting mechanism which discriminates among particles in order to produce at least two populations which vary in a desired property. The property does not have to be heat – here is one based on photonics. https://phys.org/news/2016-02-physicists-photonic-maxwell-demon.html
There have been many systems which are proved to sort and separate on a small or quantum scale. The Ranque Hilsch vortex tube is one which can operate at high power levels and gave this forum its name. If the mechanism doesn’t sort and separate - then it probably is not a “Demon”. From: Chris Zell If you gain from ambient heat, is that a Maxwell’s Demon sort of violation?
